1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * HID driver for PhoenixRC 8-axis flight controller
4 *
5 * Copyright (C) 2022 Marcus Folkesson <marcus.folkesson@gmail.com>
6 */
7
8#include <linux/device.h>
9#include <linux/hid.h>
10#include <linux/module.h>
11
12#include "hid-ids.h"
13
14struct pxrc_priv {
15 u8 slider;
16 u8 dial;
17 bool alternate;
18};
19
20static const __u8 pxrc_rdesc_fixed[] = {
21 0x05, 0x01, // Usage Page (Generic Desktop Ctrls)
22 0x09, 0x04, // Usage (Joystick)
23 0xA1, 0x01, // Collection (Application)
24 0x09, 0x01, // Usage (Pointer)
25 0xA1, 0x00, // Collection (Physical)
26 0x09, 0x30, // Usage (X)
27 0x09, 0x36, // Usage (Slider)
28 0x09, 0x31, // Usage (Y)
29 0x09, 0x32, // Usage (Z)
30 0x09, 0x33, // Usage (Rx)
31 0x09, 0x34, // Usage (Ry)
32 0x09, 0x35, // Usage (Rz)
33 0x09, 0x37, // Usage (Dial)
34 0x15, 0x00, // Logical Minimum (0)
35 0x26, 0xFF, 0x00, // Logical Maximum (255)
36 0x35, 0x00, // Physical Minimum (0)
37 0x46, 0xFF, 0x00, // Physical Maximum (255)
38 0x75, 0x08, // Report Size (8)
39 0x95, 0x08, // Report Count (8)
40 0x81, 0x02, // Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
41 0xC0, // End Collection
42 0xC0, // End Collection
43};
44
45static const __u8 *pxrc_report_fixup(struct hid_device *hdev, __u8 *rdesc,
46 unsigned int *rsize)
47{
48 hid_info(hdev, "fixing up PXRC report descriptor\n");
49 *rsize = sizeof(pxrc_rdesc_fixed);
50 return pxrc_rdesc_fixed;
51}
52
53static int pxrc_raw_event(struct hid_device *hdev, struct hid_report *report,
54 u8 *data, int size)
55{
56 struct pxrc_priv *priv = hid_get_drvdata(hdev);
57
58 if (priv->alternate)
59 priv->slider = data[7];
60 else
61 priv->dial = data[7];
62
63 data[1] = priv->slider;
64 data[7] = priv->dial;
65
66 priv->alternate = !priv->alternate;
67 return 0;
68}
69
70static int pxrc_probe(struct hid_device *hdev, const struct hid_device_id *id)
71{
72 int ret;
73 struct pxrc_priv *priv;
74
75 priv = devm_kzalloc(dev: &hdev->dev, size: sizeof(*priv), GFP_KERNEL);
76 if (!priv)
77 return -ENOMEM;
78 hid_set_drvdata(hdev, data: priv);
79
80 ret = hid_parse(hdev);
81 if (ret) {
82 hid_err(hdev, "parse failed\n");
83 return ret;
84 }
85
86 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
87 if (ret) {
88 hid_err(hdev, "hw start failed\n");
89 return ret;
90 }
91
92 return 0;
93}
94
95static const struct hid_device_id pxrc_devices[] = {
96 { HID_USB_DEVICE(USB_VENDOR_ID_MULTIPLE_1781, USB_DEVICE_ID_PHOENIXRC) },
97 { /* sentinel */ }
98};
99MODULE_DEVICE_TABLE(hid, pxrc_devices);
100
101static struct hid_driver pxrc_driver = {
102 .name = "hid-pxrc",
103 .id_table = pxrc_devices,
104 .report_fixup = pxrc_report_fixup,
105 .probe = pxrc_probe,
106 .raw_event = pxrc_raw_event,
107};
108module_hid_driver(pxrc_driver);
109
110MODULE_AUTHOR("Marcus Folkesson <marcus.folkesson@gmail.com>");
111MODULE_DESCRIPTION("HID driver for PXRC 8-axis flight controller");
112MODULE_LICENSE("GPL");
113

source code of linux/drivers/hid/hid-pxrc.c